The book Protokoly Sionskih Mudretsov (1923, Berlin, in Russian), edited by Delevskii, aims to disprove the forged Protocols of the Elders of Zion. Its author, Yakov Lazarevich (Yankel Leizerovich) Yudelevsky (pseudonyms: Yu. Delevsky, Galin, Volin, A.I. Komov, Lipin), was born February 27 or April 27, 1868, in Pruzhany (now Belarus) and died in December 1955 or January 6, 1957, in New York. He was a revolutionary participant, prominent Socialist Revolutionary, writer, and of Jewish origin.In 1892, he was sentenced to one year in Kresty prison, then exiled for five years in Yakut province under police supervision. He spent 15 months in prison and later lived in exile in Vilyuysk, teaching local children and contributing to the press. He was also exiled in Yakutsk and Grodno before emigrating to Paris after his sentence.As a member of the Socialist Revolutionary Party, he likewise participated in opposition groups, notably founding the Group of Young People's Will (later the Group of People's Will) in 1902. During WWI, he held an internationalist stance and remained abroad after the 1917 revolution. In the 1920s, he contributed to publications like Milyukov’s *Last News* and the *Jewish Tribune*, among others, and was involved with various Russian and foreign presses, including *New Russian Word*, *Le Mois*, and *Illustrated Russia*. He was an honorary member of the French Astronomical Society, vice-chairman of the Society of Philosophy and Sciences, and later a fellow chairman of the Scientific and Philosophical Society.In 1923, he joined the Republican-Democratic Club and the League against Anti-Semitism. He entered Freemasonry in 1925, initiated in the North Star lodge, attaining the 2nd degree in 1927 and the 3rd degree in 1930. He served as a legal delegate from 1930 to 1931 and remained a member until 1952, also part of the Northern Brethren lodge in Paris (1938).He presented at the Society of Jewish Engineers and Architects in 1932 and lectured at the Russian People's University. From 1933, he engaged with the Russian-Jewish intelligentsia, giving lectures at its meetings. During WWII, he resided in the USA, living in New York from 1946 to 1953. He reportedly was part of the Masonic group “Russia” in New York (1943–45) and was involved with a literary foundation there. He is buried in Arbeiter Ring Cemetery, New Jersey.